Ribbon vibrating mechanism for typewriting machines



L. B. HILL Jan. 5; 1954 RIBBON VIBRATING MECHANISM FOR TYPEWRITING MACHINES 3 Sheets-Sheet 1 Filed Jan. 19, 1952 mm ww i Z N INVENTOR LAURENCE B. HlLL L. B. HILL 2,664,989

RIBBON VIBRATING MECHANISM FOR TYPEWRITING MACHINES 3 Sheets-Sheet 2.

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INVENTOR LAURENCE B. HlLL Z BY ATl ORNEY NM mm NM 8/ m P mm 5 m Jan. 5, 1954 Filed Jan. 19, 1952 Jan. 5, 1954 L. B. HILL 2,664,989

RIBBON VIBRATING MECHANISM FOR TYPEWRITING MACHINES Filed Jan. 19, 1952 3 Sheets-Sheet 3 INVENTOR LAURENCE B:H\LL

: BY AQTORNEY standing sub-lever 3!, a link 32 and a returning spring 33. The key levers support the keys in four banks as is usual, one key lever of each bank being shown in Fig. 2. Each key lever has a pin and slot connection 34 with the forwardly extending arm of its associated bellcrank 29, these connections being staggered from bank to bank, as shown in Fig. 2, for uniform rocking of the bellcranks by the key levers. The bellcranks are all of identical size and shape and are fulcrumed on a pivot rod 35 carried by bar 13. The upstanding sub-levers 3| are of graduated length and are fulcrumed at their lower ends on a pivot rod 35 carried by bar H6. The key levers are fulcrumed on a pivot rod 3! carried by bar 15. The links 32 connect the upper ends of sub-levers 3| with the heels of the type bars. The links 3!) connect the upwardly extending arms of the bellcranks with the sub-levers 3! intermediate the ends of the sub-levers. The returning springs 35 are connected to the upwardly extending arms of the bellcranks to restore the type bar actions to normal rest position.

The type bar action system is not claimed per se herein but is disclosed to show one suitable type action system for actuating the improved ribbon vibrating mechanism. It will be obvious to those skilled in the art that other manually or power operated type action systems may be employed. The improved ribbon vibrating mechanism now will be described.

The ribbon vibrator 38 is located as usual midway the sides of the machine, is rectilinearly reciprocable up and down to cover and uncover the printing point, and its upper or head portion is formed with the usual pair of laterally spaced ribbon guides through which the inked ribbon (not shown) is threaded. The head portion of the vibrator is slidably held against the rear face of a forwardly offset upper portion of the type bar guide 22 by two bent guide lugs 39 which are formed on said vibrator portion and slidably embrace the parallel vertical side edges and the front face of said type bar guide portion. Below said guide lugs 39 the vibrator has a narrow lower or stem portion which is provided at its lower end with a pair of laterally projecting guide lugs 48. The lower portion of the type bar guide, which is clamped to the front face of the type bar segment by the screws 23, is formed with a longitudinal channel M in its rear face. This channel overlaps the vertical side edges of a narrower slot 42 in the type bar segment. Slot 42 extends downward from the upper chordal edge of the segment midway said edge, and the guide lugs 40 slidably engage the side edges of channel 4| and the opposed faces of the segment and channel. The vibrator is thus guided at different points along its length against fore and aft and sidewise movements to minimize possibility of the vibrator canting, jamming or bending in use.

At a point along its length between, and spaced from, the two pairs of guiding lugs 3939 and 4040, the stem portion of the vibrator is provided with a pair of rearwardly extending and laterally spaced ears 43 to which are fixed the ends of a horizontal pin 44 on which there is Journalled an anti-friction roller or sleeve 45. The vibrator is reciprocated by a bellcrank which is spring biased to a normal rest position in which said bellcrank supports the vibrator in a normal lowered rest position wherein the upper edge of the ribbon is below the printing point and the type cannot strike the ribbon.

The vibrator reciprocating bellcrank comprises a rock shaft or long axle 46 which extends horizontally across the machine behind the frame plate l2 from the right hand side plate H to a point slightly to the left of the longitudinal center line of the machine. This shaft has fixed thereto a forwardly extending rock arm 41 and a pendent rock arm 48. The shaft 46 is journalled at its left hand end on a pivot screw 49 threaded through a bracket 59 secured to frame plate I 2, and is journalled at its right hand end on a pivot screw 5i threaded through side plate ll. Bellcrank arm 41 is located medially of the sides of the machine and has a longitudinal slot 52 in its forward end through which passes the pin 44 and the anti-friction roller or sleeve 45. Bellcrank arm 48 is fixed to shaft 46 adjacent the right hand end of said shaft and has a laterally offset lower portion which is located at the outer side of frame plate I I and is connected with the upper portion of said arm by a horizontal intermediate stop portion 48a of the arm which extends through a clearance aperture 53 in frame plate II. The lower portion of arm 48 is formed with an edge which curves in a substantially circular are at the front and lower end edges of said arm portion to provide a rearwardly and downwardly curved cam edge 4%. A horizontal stud 60 projects outward from the lower portion of arm 48 between the stop portion 48a of the arm and said curved edge of the lower portion of the arm.

A return spring 54 is connected to bellcrank arm 48 and to a stop bracket 55 to bias the bellcrank and vibrator to their respective rest positions, which positions are adjustable by adjustment of said bracket. Bracket 55 has an arm extending inward through aperture 53 and carryinga stop 56 abuttive by stop portion 48a of arm 48 to arrest spring return of the bellcrank and vibrator. This bracket 55 and stop 56 are adjustable about the axis of the bellcrank, said bracket being journalled on hub 51a of a nut 51 which is threaded on pivot screw 5|. The bracket has an arcuate slot 58 concentric with said screw 5| and through which extends a clamping screw 59 which is threaded into frame plate II to lock the bracket in adjusted position. The cross plate I2 and segment carrier 2| are provided with clearance notches [2a and 2m, respectively, for the bellcrank arm 4?.

The spring-returned bellcrank 464148 is rockable from its rest position by a springreturnecl actuating mechanism which is drivable from a normal rest position by each of the type bar actions on their printing strokes. Said mechanism is variably settable by a manually operable setting mechanism to lift the vibrator on the printing strokes of the type bars to present any selected one of three different zones of the ribbon for type impact, or to render said actuating mechanism ineffective to rock the bellcrank from rest position. This bellcrank actuating mechanism, its setting mechanism, and certain vibrator overthrow preventing stop means are mounted on the main frame of the machine and now will be described.

The actuating means for the bellcrank 46-4l48 comprises a type action operated universal bar El, a variably settable actuating link 62 reciprocable by the universal bar, a spring 53 for restoring the bar to rest position, and an adjustable return stop device hereinafter described for the bar. The universal bar 6| is a straight bar which is fixed adjacent its upper edge on a horizontal rock shaft 64 and depends from said shaft with its rear face, adjacent the lower edge diseased or the bar, normally located j closely in front of the upper end; portions 29a" of the type action bell'cranks 2 Sjif or forward rocking. of the universal bar by'theirespective bellc'ra'nks on the printing strokes of'theityp'e actionsofwhich they are a part. Theuniversa'l bar rock"shaftisjjournalled' at'itsleft han'dendion a pivot'scr'ew SFthreaded through frame plate. Ill, The'rock shaftextends through a notch llain' frame plate I'I an'd'hasa reduced -righthand'end portion Mai journalled in a brack'et E5 which isfixed to plate that the'outer' side of 's aid'plate.

A hub 67, whichis' adjustable around the rock" shaft between plate ll andfasheetmetal bracket and heldin adjusted" position to "the? shaftby a set screw 68, is formed-with apendentarm 69 and anupstanding arm Arm 69 carries, a horizontal pivot- H to'which the front end'oflink fi2=is connected: The return spring 63 has'its rear end connectedto link Biandits front end'connected tothe lower end of arm 6'9below pivot" 1 l The-upstanding arm lil 'ha-s fixed to its upper end anoutwardly projecting padded'stop l2which normally abuts the rear edge ofan mastanding stopfinger orlug H'formed'on the sheet metal bracket 65; This finger is bendable fore and aft of-the machine to adjust-the rest position of'th'e universal bar.

The reciprocable or pitman link 52 is formed of sheet'rnetal and has-two longitudinal slots in its-rear endportion forming three fingers whose rear end portions are" bent inward to provide three bellcrankactuating-lugs or fingers 14; 15"

This setting means shifts the pitman link 62" around its pivot "H to change the setting of the actuating mechanism, andit is releasably detentablein four different-positions in which it supports-and guides thepitman link to reciprocate longitudinally in any-selected one of four different-paths. Thissetting mechanism also serves other purposes hereinafter described.

The-operating handle or knobTl'of the setting mechanism is detachably fixed on the forward e nd'of a'short handle'shaftw'by a set screw 19 and may beadjusted-around'saidshaft by looseningsaid screw and turning the knob" relatively to theshait. The shaft extends' looselythrough an upstanding front cover plate till-of the typewriter. and is j ournalled in a short bearing sleeve 8 I. the-reduced forward end portion of which has aadriving fitin -ahole ina main fra'mepart llb extending-inwardly transversely of the machine from. the right hand-side plate 1 I J Ash'ort rock arm 82-has -a-hub' portion detachably held to" the -rear end of the'shaft "by a set screw 83 and adjustable around 'said shaft when the screwis loosened. The knohabuts the front face of plate-Mend therock arm abuts the rear end ofsleeve 8| to holdthe knob,'shaft and rock arm against movement fore and aft of the machine. The connected 'knob', shaft and rock arm serve as a retainin'gdevice for the front, cover plate 80., Knob 11' isprovided onits front face with a pointer 84 toselectively .point to ,thedesired one of the four setting indicating indicia or" letters, "Rf" Mi. B and, SI provided on thefront'coverplate.80.

A link 851is connected lat; it'sfyupp'er end to rock". arm 82 and at its lower end, to, the forward end of a, sheet metal lever 86'? lie'ver', 815. has a flat mid-portion held" against the outeffacesoffa' side'i plate I Ii by a: shouldered p'ivot's'crew 81, and its forwarder-m is bent to pas's' through a, clearance hole 88in said'sicle' plate and its rear arm is bent, to offset" the rear portion of'f'said" arm from the outer face offsaid plate, The pitmanlink e'xtendsacross the-outer'face"offthe offset rear por; tion oflever 86' an'd'ha's, adjacent'itsrear end; a longitudinal guide s10t'89 through which extends the shoulder portion'fiofi a) shoulderedfhorizontal supporting; guiding. and retainingjscre'w for said link, whichyscrewis threadedinto'the. lever" adjacent the rear end of" said lever.

To exactly determine the foursetposition's of the abovedescrib'ed knob-operated setting means, to positively limit the'-rang'e of'fmovementofi'said means, and to releasably' detent said" means in each set position, an adjustable detent device and I co'a'ctive adjustable stops are, provided; This device consists of aive'rtic'all'y adjustablesheetmetal rack" 91" having four 'V-shap'ednotchesj 92 in' its;

forward edge, a ,detent lever 93' connected"to the rear'arm of 'le'ver' 86"b'y,fa horizontalpivot'M; a' detent roller 95 'journalle'd 'on 'a" horizontal pivot" 96 at the lower end of a pendent arm of lever 93;

and a pull spring 91'connectingan'upwardly and, forwardly extending arm of lever'93'ftothe rear arm of 'lever8 6" to snapthe rollersuccessively into. the notches 92' as 'lever1B6 isTro'ckedQ, Theflrackill has two forwardly extending 'stop fingers safandi 99 respectivelyjabutted' by the roller 95 when the roller" is fully seated, in'thejuppiermost and lowermost ones of the notches}STtOTpfositiVelygarrest shifting of the setting? means. The rack 9lfis clamped to the outer.face'of"the'jframesideplate' l I in vertically adjusted position, by two clamp;-

ing screws IOOan'd] 0] whichpa's's through vertical slots in the rack andare 'thre'adedinto said"sidel plate. Desirably, the lever 86 is provided with'a' clearance hole I02 to afford convenient a'ccessto I04 and whicha're steppedseriatim rearward and downwardlrelatively to each other different distances from the",lever' pivot 8'! 'for selective" presentation ,in "front" of the'round'ed =lower :front edge portion. of "the rock arm' 48 of the ribbon" vibrator actuatingbellc'rank id- 48? The up;

per'edges of these stop lugs preferably ,ar'e'oeveled rearward and downwardfor" easy coaction' with the cam edge 4860f fbellc'rank"armr lflf as'hereinafter more'fullyexp-lained. V

In Figs; 1, 2 "and? the ribbonwibrating meoh A anis'm is shown set; for vibratingthe -ribbonto its highest limit of movement 'f01 impact of the type on a lowermost longitudinal'zoneof the 'rib-' bon. In this setting, the'detent roller-95 is'seate'd in the lowest one of the rack" notches 92 and-om the lower stop finger!!!) on the rack, the pointer Mon knob "points totheindicating"letterR v on the front cover plate;,the actuating lug' "on the pitman link .62 is behind and in" contact with the stud fill on arm, 4810f 'the,'vibratoractuating bellcrank1..in the. rest. position. of jthelparts'jand" rocks the bellcrank into the positionlshown in;

Fig. 3 on the printing stroke of any one of the type bar actions, and the three stop lugs I03, I04, and I are lowered out of the path of forward movement of arm 48 of the bellcrank. To prevent overthrow of the vibrator in this setting of the ribbon vibrating mechanism it is desirable to provide an overthrow stop which acts as closely to the vibrator as is convenient. To this end a padded overthrow stop I06 is mounted over the bellcrank arm 41 to be engaged by the upper edge of said arm near the pin-and-slot connection 44, 45, 52 to the vibrator, as shown in Fig. 3, substantially as a type bar action completes its printing stroke. Stop I06 is mounted on a bracket I01 secured to the frame cross plate I2.

When knob I1 is turned to register the pointer 84 with the setting indicating letter M, the actuating lug I5 on the pitman link 62 is positioned behind stud 60 and spaced slightly to the rear of the stud to afford such initial lost motion between said lug and stud that the vibrator is lifted only far enough on the printing strokes of the type bar actions for type impacts on a medial longitudinal zone of the ribbon. In this setting of the mechanism, the overthrow stop lug I03 on lever 86 is, in the rest position of the parts, positioned opposite and spaced forwardly from the rounded lower front edge portion of bellcrank rock arm 48 to be engaged thereby on the printing strokes of the type bar actions to prevent overthrow of the ribbon.

Turning of the knob to register the pointer with the indicating letter B positions the actuating lug I6 behind stud 60 and spaced still farther rearward from said stud to afford such initial lostmotion between said lug and stud that the vibrator is lifted only far enough on the printing strokes of the type bar actions for type impacts on an uppermost zone of the ribbon. In this setting the overthrow stop lug I04 on lever 86 is positioned in front of and spaced from the rounded lower front edge portion of bellcrank arm 48 to be engaged thereby on the printing strokes of the type bar actions to prevent overthrow of the ribbon.

In the stencil setting, shown in Fig. 4, the knob is turned to register the pointer with the indicating letter S and the pitman link is entirely inoperable on the Stud 68, so that the bellcrank and vibrator remain in rest position during actuation of the type bar actions. In this setting, the detent roller 95 is seated in the uppermost one of the notches 92 in rack 9i and also is engaged under stop finger 98 on said rack. Also in this setting, the stop lug I65 on lever 86 is positioned in front of, and in contact with, the rounded lower front edge portion of bellcrank arm 48, as shown in Fig. 4, to positively hold the bellcrank and vibrator from movement out of rest position.

The stop lugs I03, I04 and I05 on lever 86 will each coact with cam edge portion 48b of bellcrank arm 48 to cam the bellcrank and vibrator back toward rest position in the event of the vibrator being stuck in an elevated position on the type bar guide when a setting change for a shorter ribbon throw is made, and this cam action also prevents a stuck vibrator and bellcrank from blocking a change of setting. In moving from the R to the M setting with the vibrator stuck in an elevated position on the type guide, the stop I83 will engage cam edge 48b and either dislodge the stuck vibrator for return to rest position by spring 54, or will force the bellcrank and vibrator to its actuated position for typing on the middle ribbon zone, so

that the type will strike the desired part of the ribbon in any event. In shifting to the B setting from the M setting the stop I04 will act in a similar manner on the cam edge 48b in the event the vibrator is stuck. In shifting into the stencil setting stop I55 always will coact with cam edge 481), if the vibrator is stuck out of rest position, and will force the vibrator and bellcrank into rest position and positively hold them locked there until the setting is changed. The beveled upper edges of the stop lugs Hi3, I04 and I65 make the above described cam action easier or smoother.

The spring urged detent roller will coact with the pointed teeth separating the rack notches 32 to complete any setting change if the knob TI is released before the roller is fully seated in a notch. The pull lugs I4, I5 and "I6 and the stop lugs I03, I64 and I05 are bendably adjustable fore and aft of the machine for accurate coaction with stud 66 and arm 48. The various other adjustments previously described make possible extremely accurate control of the ribbon vibrator. The spring-returned universal bar is always free to return on the return strokes of the type bar actions even if the vibrator should stick in an elevated position on the type bar guide.

I claim:

1. A typewriting machine having a ribbon vicrating mechanism which comprises a setting handle, a setting lever extending fore and aft of the machine and connected at its forward end with said handle and fulcrumed between its ends for up and down rocking thereof by said handle into different set positions, a springreturned universal bar stroked forwardly by type actions of the machine on their printing strokes, a return stop for said bar, a spring-returned bellcrank having forwardly extending and pendent arms and rockabie about an axis extending transversely of the machine, a ribbon vibrator pivotally engaged with the forwardly extending arm of the bellcrank and guided for up and down reciprocation thereby, a return stop for said bellcrank, an actuating link extending fore and aft of the machine and having a pivotal connection at its forward end with the universal bar by which it is reciprocable forwardly and backwardly respectively on the type-actionimparted and spring-returned strokes of the universal bar, said link having also a supporting pin-and-slot connection with said lever by which it is rockable up and down by said lever about said pivotal connection, means for releasably detenting said setting handle and lever in selectively set positions, limit stop means for determining two opposite limit settings of the handie and lever, a plurality of stops carried by the rear end of said lever and stepped progressively rearwardly and downwardly relatively to each other for selective presentation in front of the pendent bellcrank arm to control the extent of movement of the bellcrank from its spring-returned position, the rear and lowermost of said stops in one or" said limit settings of the lever bein presented in front of and in contact with said pendent bellcrank arm to lock the bellcrank in returned position, and means carried by said link and pendent bellcrank arm for establishing in each setting of said lever, except said lastmentioned one of said limit settings, a pull connection between said link and arm, each of which pull connections is effective to rock said arm forwardly a different distance.

sii jien etthe handle andleverfia's'pring urged cetent {roller carried "by the lever to move up and down'alon'g said rack edge and seat in 'said upstanding *rack I'ia-vingia-ISW'pf 'nbtliesfih 96m W longitudinal edge thereof, mere-wash *set' po- 1 notches, a'n'd two limitstopscarried by said-"r'ak atoppositeends of said recesses-and respectively -engageable by said roller as it'*-'s'eats in earnest bries of the twoendmostmotches of said rowbf n'otches.

3. -A typewriting machine, as 'c'laimed in}laim l,':wh'erein the pull connection establishingmeans comprises a :lateral projection on the pendent bellcrank arm, and a plurality of laterally extending projections 'onsaid link' stepped progres- "sively irearward and downward relatively lt'o e'ach other and selectively presentable behind said projection on "said .ar'm toestart ro'cklng "of said 'arm'atdifierent points in-ttheitype-iactionfiimparted strokes of :the universal bar.

4. A typewriting machinejas claimed-inclaim '1, wherein said pendent bellcrank'arm andweaCh of said stops on'the lever have surfaces coactive, during rocking of :the lever from one 'of its limit settings to that in which the bellerankis locked in returned-position, to camthe bellcrank toward its returned position in-the event of the vibrator being stuck inelevated position.

5. A typewriting machine :having a ribbon vibrating mechanism comprising a "spring-returned bellcrank having forwardly extending iand-pendent-arms and rockable about anaxis extending transversely of the machine, a ribbon vibrator pivotally engagedwith the forwardly extending arm for up and down reciprocation to vibrate the inked ribbon of themachine-in toand out of type impact receiving position, a spring-returned rockable member located forward of tli'epen'd ent belle-rank arm and automaticallyforwardly re kab'le on theprinting strokes of the types of the machine, a lever having an arm whiche'xten'ds rearward toward the pendent 'bellcrar'ik amend is manually settable up and'down about an axis extending transversely of the 'n-iac hine a bellcra'nk actuator having a pivotal connection at its forward end with said memberand a fore and aft vslidable connection with said lever arm in rear of said pivotalc'onnection, which two connections support the actuator for fore and aft reeiprocationan'd for upand down setting movements about said pivotal connection, means for releasably detenting said lever' arm in upper'and lower limit settings -and in at least one intermediate setting, and a plurality of lateral projections stepped rearward and downwardirelatively to each other on the actuator and selectively presentable by movement of said lever arm into its respective lower and intermediate settings to exert a forward pull on the pendent bellcrank arm at the same distance from the bellcrank axis on the forward rocking strokes of the spring-returned rockable member.

6. A typewriting machine, as claimed in claim 5, having on said lever arm an abutment which is presented in front of and in contact with said pendent bellcrank arm while said lever arm is in its upper limit setting to prevent movement of the bellcrank from its spring-returned position.

7. A typewriting machine, as claimed in claim 5, in which the detenting means detents the lever arm in two intermediate positions, the actuator has three of said rearwardly and downrelativly to each;

whichabutment 'e selectively presenta eenter the ens 't b'llcr arik'arm by -the'r -tive Winter-mediate settings et the i'ii -1imit i'forward swinging of said l and the lowermost one of whic engaged with the 'rr'ont or "said *bellc'rank frm in the upper limit setting of"thelever hf'm, "in which "a stop is mounted on the-main "f "above theiforwardly extending arm of th if crank for "engagement thereby to limit aware movement thereof "while the lever "arm is in its lower :limit setting.

8. A 'typewriting machineya's claimed fifclaiin '5, having a =main frame 'on WhiCh "the spii'ngreturned bellcrank, 'le'v'er, spring retiirned -mem ber; actuator and' detentin'g meansare mounted, the forwardly ext-ending "arm of the "belldrank being 'located medially of thesid'es'of the franie and its pendent arm extending laterally outward through oneside of the frame and then downward outsidepf that side of the f ramefthe rearwardly extending arm of the lever and alsof t'he spring-returned member; actuator and 'detenting means all being locatedat the'outer side of said one side of ;the :frame, adjustable-return stop means for the spring-returned,-bellcrank, said machine also having adjustable return means for the spring-returned meinber mountegzl on the *frame at the outer'side of said one frame side.v i

I A typewriting machine having a b'rating mechanismcomprisin'g'a ribbon vibi 'or guided "for up, a eqown reciprocation, a bellcrank having forwardly extending and be dent arm's and ro'c'kable about an axis wh' transversely of the inahinajaiidsh-pull n ction between "the vibr ator andfthe "forwardly-e)?- tending bellcrank a m, aj retur strip re t le bellcr'af-nk, a return sprin connect h a k ibf sir n'd l ri n w ta a said return 'stojpto yildingly hfold t p ll s rewed t ma ain an mk a'r P9 of the finachine below the writ r turn d a' ih ce ves i h? rrm i isi k' iof yee 'e it. a "p thj a b re nd a t 1 t e me b'y a 'm'eahs anq'extendin'g t'rarisvrselycf the inaii forward or said pendent bellcrarikfa -link ex'tnding re'arward from" dheld'to pivotf'a rtiirnstopffor saidirians afidlfiik, a nanny projecting stud on the pendent bll crank arm, a plurality of bull lu 'gs extending laterally froiirsaid Iinkand steeped progress vely rearwaraaria 'd wnwara relatively to each other different distances irem said pivot iiur selective presentation behind bald stud to rock the bell crank different distances from its returned position. and means for releasably detenting said link in different rocked positions around said pivot for longitudinal reciprocation by said pivot, in one of which rocked positions of the link said stud is out of the paths of movement of all of said pull lugs, and in each of the other ones of which positions of the link a difierent one of said pull lugs is effective on said stud to rock the bellcrank from its returned position.

10. A typewriting machine, as claimed in claim 9, in which said detenting means comprises an upstanding stationary member having a row of notches in one longitudinal edge thereof, a member manually rockable up and down and supporting said link to rock therewith and reciprocate relatively thereto, a two-armed lever pivoted on said rockable member to rock fore and aft of the machine, a detent roller journalled on one arm of the lever to roll along the notched edge of said stationary member when the rockable member is rocked, and a spring connecting the rockable member and the other arm of said lever to yieldingly press said roller to said edge of the stationary member.

11. In a typewriting machine, a type bar supporting segment having an upper edge and a slot extending downward from said edge midway the ends of the segment, an upstanding type bar guide having a type bar and ribbon vibrator guiding upper portion above said segment edge and a lower portion detachably clamped to the front of the segment and overlying said slot, said type bar guide having a longitudinal channel in its rear face wider than and straddling said segment slot, a ribbon vibrator having a ribbon guiding head portion and a pendent stem portion, the head portion of the vibrator having a pair of oppositely disposed guide lugs slidably engaging the longituddinal edges and front face of said unper portion of the type bar guide and slidably holding said head portion of the vibrator to the rear face of the said tyne bar guide portion, the stem portion of the vibrator having a pair of oppositely disposed and laterally projecting guide lugs at its lower end slidably confined between the segment and type bar guide at opposite sides of said segment slot with their outer ends slidably engaged with the side walls of said channel in the type bar guide, a pair of laterally opposed ears extending rearward through the segment slot from the stem portion of the vibrator intermediate said two pairs of guide lugs, a horizontal pin extending between and secured to said ears, a roller journalled on said pin, a vibrator actuating arm extending forward toward the segment and having in its forward end a longitudinal slot in which said roller is engaged, and means for vibrating said arm up and down respectively on the printing and return strokes of the type bars of the machine.

12. A typewriter having a ribbon vibrating mechanism which comprises a ribbon vibrator, a

bellcrank rockable about an axis extending transversely of the machine, said bellcrank having a forwardly extending arm connected to the vibrator to reciprocate it up and down and having also a pendent arm which is formed with laterally 12 intermediate portion of the pendent bellcrank arm, and a return spring connected to said bracket and pendent bellcrank arm and normally holding the intermediate portion of said pendent arm rocked against said stop.

13. In a ribbon vibrating mechanism for a typewriting machine having a ribbon vibrator actuating bellcrank and means for rocking the bellcrank in one direction about its axis on the printing strokes of the types of the machine, the com bination of a bracket adjustable about the axis of the bellcrank, a spring connected to the bracket and bellcrank to return the bellcrank to a rest position, and a return stop for the bellcrank held to said bracket in the path of return movement about the bellcrank axis of a part of said bellcrank.

14. In a typewriting machine having an upstanding detachable front casing plate, a main frame having a transversely extending portion abutted by the rear face of said plate, and ribbon vibrating mechanism having a part selectively settable to effect different extents of vibration of the inked ribbon of the machine, the combination of setting means for said part comprising a bearing sleeve extending fore and aft of the machine and having its forward end secured in an aperture in said frame portion, an oscillative shaft extending through said front plate and bearing sleeve, a control knob fixed on the forward end of said shaft and abutting the forward end of said sleeve and the front of said plate, a rock arm detachably fixed on and rotatively adjustable about the rear end of the shaft and abutting the rear end of said sleeve, and means connecting said rock arm and said settable part of the ribbon vibrating mechanism for selectively setting said part.

15. A typewriting machine, as claimed in claim 14, having a spring-urged detent carried by said connecting means, an endwisely adjustable rack on the main frame with which said detent is coactive to releasably maintain each of at least three selected settings of the ribbon vibrating mechanism, two limit stops carried by said rack for engagement by said detent to determine two limit settings of said mechanism, and means on said knob and the front of said plate coactive to indicate the respective settings of said mechanism.

LAURENCE B. HILL.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 874,338 Hess Dec. 1'7, 1907 1,072,148 Myers Sept. 2, 1913 1,121,042 Petermann Dec. 15, 1914 

